Summaries for Polymyositis

NINDS
:54
Polymyositis is one of a group of muscle diseases known as the inflammatory myopathies, which are characterized by chronic muscle inflammation accompanied by muscle weakness. Polymyositis affects skeletal muscles (those involved with making movement) on both sides of the body. It is rarely seen in persons under age 18; most cases are in adults between the ages of 31 and 60. Progressive muscle weakness starts in the proximal muscles (muscles closest to the trunk of the body) which eventually leads to difficulties climbing stairs, rising from a seated position, lifting objects, or reaching overhead. People with polymyositis may also experience arthritis, shortness of breath, difficulty swallowing and speaking, and heart arrhythmias. In some cases of polymyositis, distal muscles (muscles further away from the trunk of the body, such as those in the forearms and around the ankles and wrists) may be affected as the disease progresses. Polymyositis may be associated with collagen-vascular or autoimmune diseases, such as lupus. Polymyositis may also be associated with infectious disorders, such as HIV-AIDS.

NIH Rare Diseases
:53
Polymyositis is a type of inflammatory myopathy, which refers to a group of muscle diseases characterized by chronic muscle inflammation and weakness. The muscles affected by polymyositis are the skeletal muscles (those involved with making movements) on both sides of the body. Although the disease can affect people of all ages, most cases are seen in adults between the ages of 31 and 60 years. The disease is more common among women and among black individuals.
The exact cause of polymyositis is unknown. The disease shares many characteristics with autoimmune disorders, which occur when the immune system mistakenly attacks healthy body tissues. In some cases, the disease may be associated with viral infections, connective tissue disorders, or an increased risk for malignancies (cancer). Diagnosis is based on a clinical examination that may include laboratory tests, imaging studies, electromyography, and a muscle biopsy. Although there is no cure for polymyositis, treatment with corticosteroids or immunosuppressants can improve muscle strength and function.

Trial to Evaluate the Efficacy and Safety of Abatacept in Combination With Standard Therapy Compared to Standard Therapy Alone in Improving Disease Activity in Adults With Active Idiopathic Inflammatory Myopathy

2016 American College of Rheumatology/European League Against Rheumatism criteria for minimal, moderate, and major clinical response in adult dermatomyositis and polymyositis: An International Myositis Assessment and Clinical Studies Group/Paediatric Rheumatology International Trials Organisation Collaborative Initiative. ( 28385805
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